Let’s Talk About It

Once the liquid in the strips has risen up the filter paper to about 2 cm from the top of the beaker or container, have students carefully remove their strips and lay them on a paper towel to dry. Ask students, What colors do you see on your strips? Usually, three color bands will form: Blue at the top, followed by yellow or green, followed by red at the base. Ask, What do these findings tell us about the mystery liquid? How many substances were mixed together to make the liquid?

The strips may be preserved in a notebook or displayed in class after they are dry. Encourage students to extend their discoveries to other situations. For example, ask, Since several different things were mixed together in the mystery liquid, do you think other types of liquids also might be mixtures of different substances?